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| n | a(n) |
|---|---|
| 0 | 0 |
| 1 | 0 |
| 2 | 0 |
| 3 | 1 |
| 4 | 26 |
| 5 | 595 |
| 6 | 14155 |
| 7 | 363944 |
| 8 | 10206700 |
| 9 | 312193524 |
| 10 | 10380710220 |
| 11 | 373619597736 |
| 12 | 14490750497432 |
| 13 | 603032132116336 |
| 14 | 26818416624389936 |
| 15 | 1269883590624201344 |
| 16 | 63806666669904903808 |
| 17 | 3391580011320726010880 |
| 18 | 190174443042558311293440 |
| 19 | 11220246602286014617751040 |
[0,0,0,1,26,595,14155,363944,10206700,312193524, 10380710220,373619597736,14490750497432, 603032132116336,26818416624389936, 1269883590624201344,63806666669904903808, 3391580011320726010880,190174443042558311293440, 11220246602286014617751040] |